Modified polymers that are modified by a compound containing a nitrone group (nitrone compound) have been known conventionally as polymers contained in rubber compositions for use in tires and the like.
Patent Document 1, for example, describes a rubber composition comprising, per 100 parts by weight of a diene-based rubber containing from 5 to 100 wt. % of a modified butadiene rubber, from 10 to 120 parts by weight of silica; wherein the modified butadiene rubber is butadiene rubber with a cis-content of 90% or greater modified by a nitrone compound having a nitrogen-containing heterocycle per molecule (Claim 1). Additionally, Patent Document 1 describes modification by a nitrone compound causing heat build-up to decrease (paragraph [0006] and the like).